Outdoor navigation systems designed for vehicles use global positioning system (GPS) signals to find position and find a route to a destination, both of which are expressed and displayed in terms of two-dimensional space. For outdoor navigation applications, determination of a vertical location, such as a level within a building, is unavailable. Further, for most outdoor land navigation, vertical location, such as level within a building, is irrelevant.
However if navigation is to be provided for a pedestrian within a building, requirements different from those present in outdoor navigation will present themselves, and the failure to fulfill these requirements has frustrated attempts to solve problems related to indoor navigation. If they can be accurately determined, floor levels in an indoor navigation system may be used to accurately guide the user from one part of a building on a first floor to a second part of a building on a different floor. Additionally, frequent updates to a vertical level will be needed to track changes in user location between levels.
Most if not all related-art systems suffer from problems of inaccuracy that compromise usability.
One of the common methods is measuring the strength radio signals on a floor level. Such radio signals are broadcast by WI-FI routers, IEEE 802.15.4 Wireless Sensor Networks or any other radio-transmitting device. The accuracy and performance of these signal strength methods are unsatisfactory, and additional problems arise with such techniques in that they will require a network set up in the building. Further some of the radio networks will require radio transmitters to be installed in pre-determined patterns to support floor detection. Such requirements immediately limit the use of radio network based methods to a handful of buildings. For example, these techniques are of limited value in exhibition halls or parking garages that have no permanent WI-FI networks installed.
An alternative, called, “fingerprinting,” is labor heavy in that it requires detailed survey of each and every floor. Effectively a ‘radio wave fingerprint’ of each and every floor is plotted from all possible locations on that floor level. Site survey is a manual process and therefore is costly and time consuming. Another disadvantage of fingerpring systems is that behaviour of transmitters change in a building over time, requiring site survey to be repeated periodically and user systems must be updated with new survey results.
Systems and methods that provide an accurate and updated determination of a vertical level within a building would provide a competitive advantage in the marketplace.